With the market development of mobile Internet and the popularity of intelligent terminal, the volume of data services has increased rapidly. Wireless data services provided by operators are increased by nearly 50 times from 2006 to 2009, and CISCO forecasts that the wireless data services in 2014 will increase more than 15 times from 2010. However, the third generation of wireless mobile telecommunications technology (3G) network is far from satisfying users' needs that grow rapidly, even the Long Term Evolution (LTE) may not completely satisfy all demands in the future.
A wireless local area network (WLAN) can be used to supplement and collaborate current cellular technology, and can help the operators to solve problems in data service shunting, the problems include sudden increase of data traffic of cellular networks, excessive consumption of wireless resources, and network overload.
As current local hot spots, the WLAN coverage, with cellular wide area network (WAN) of 3G/4G (the fourth generation of wireless mobile telecommunications technology) have become necessary in future wireless communication. In a process of heterogeneous network interconnection, LTE-WLAN heterogeneous network switching mechanism is a core problem of heterogeneous network interconnection.
In order to guarantee a secured switch from the LTE to the WLAN in the 3rd Generation Partnership Project (3GPP), Extensible Authentication Protocol (EAP)—Authentication and Key Agreement (AKA) protocol are used as a standardization switching process of the LTE to the WLAN in 3GPP standard. The EAP-AKA protocol can achieve authentication between a user equipment (UE) and a home subscriber server (HSS), and establish a shared key between the UE and an access point of the WLAN.
However, as the EAP-AKA protocol involves a re-authentication process during a switching process, a main reason that EAP-AKA switch failed is timeout of time delay. According to statistics, process time of the re-authentication process is 46 percent (46%) of the entire time delay of a whole EAP-AKA switching process on average. If the process can be designed optimally, switching time can be decreased, thereby avoiding LTE to the WLAN switching failures caused by timeouts.
Therefore, optimizing the switching process from the LTE network to the WLAN of the terminal and avoiding switching failures caused by long switching time are problematic.